The present invention relates to a disposable needle guide system for a medical imaging instrument, in particular an ultrasonic transducer, for guiding a needle into a selected location of a patient relative to the imaging instrument, for use in percutaneous interventional procedures, such as fine needle aspiration, core biopsy, amniocentesis, and drainage.
A great number of needle guide systems for use with ultrasonic transducers and the like are known in the art. Most of them are confined to be used with a transducer of particular geometry which is a considerable drawback in consideration of the considerable number of ultrasonic transducers of differing geometry on the market.
Another problem with most known needle guide systems is that they accept only one diameter size of needle, and that, therefore, their use with needles of different size necessitates the change of one or several parts. Present systems also suffer from the drawback that the user has to assemble the system from a number of parts. In addition most known needle guide systems require some sort of adapter which may constitute a substantial investment on its own. Also, such adapters may be lost or mislaid between individual percutaneous interventions.
A further problem with many known needle guide systems is that they are not truly disposable, that is, they are not easy and cheap to manufacture and, therefore, tend to be re-used, even if not suited or designed to be repeatedly used. They thus may constitute a risk to patients when being re-used improperly.
The present invention seeks to avoid the aforementioned problems.
It is an object of the present invention to provide a needle guide system of the aforementioned kind which can be adapted to transducers of varying shape, in particular ultrasound transducers.
It is another object of the present invention to provide a needle guide system of the aforementioned kind which has improved flexibility and functionality in comparison with needle guide systems presently in use.
It is an additional object of the invention to provide a needle guide system accepting needles of varying diameter without the need for exchanging parts.
It is a further object of the invention to provide a needle guide system which enables the user to choose between an adapter-based solution and a solution where a disposable device is directly fit to the transducer.
It is a particularly important object of the invention to provide a truly disposable needle guide system, that is, a system which cannot be re-used at all or with considerably difficulty only.
Further objects of the invention are evident from the following short description of the invention, the attached drawings illustrating a preferred embodiment, the detailed description thereof, and the appended claims.
According to the present invention is provided a needle guide system of the aforementioned kind, comprising a needle guide assembly and a mounting assembly for attaching the needle guide assembly to a transducer, the mounting assembly comprising self-destroying means effective on dismounting.
It is preferred for the needle guide assembly to comprise needle guide means accepting needles of different diameters, in particular needles from three to six different diameters.
It is also preferred for the needle guide means to comprise a revolver mounted in a stepwise lockable revolving manner on a journal clip.
The journal clip is mountable on the mounting assembly. According to the invention it is possible to provide a journal clip which can be mounted in two or more angular or height positions in respect of the mounting assembly.
According to a preferred aspect of the invention, the mounting assembly comprises an adapter mountable on a transducer, an attaching clip mountable on the adapter and a locking clip mountable on the attaching clip. It should be understood that the attaching clip is interposed between the adapter and the locking element on which the needle guide assembly is mountable.
It is however also possible for the attaching clip to be directly mountable the transducer; the portion of the transducer at which the attaching clip is mountable should be designed in a manner functionally corresponding to the mounting portion of the adapter. In such case no separate adapter will be needed. The variant of the needle guide assembly in which mounting portion of the adapter is comprised by the transducer is fully encompassed within the present invention.
It is preferred for the adapter to be of a generally abutable shape in respect of the transducer to which it is intended to be mounted in a transducer encircling position. The adapter preferably has two free ends provided with a cooperating snap connection which is closed on mounting and which is preferably not easily dismountable by hand.
According to a preferred second aspect of the invention the attaching clip comprises a base and first and second pairs of prehensile organs extending from the short or lateral ends of the base (or from positions close to the short ends) in opposite directions. A rough approximation of the general shape of a preferred attaching clip of the invention are two letters C joined back-to-back but not necessarily of the same size. The first pair of prehensile organs, such as claws, is designed in a manner to enable it to grip a U-formed portion of the adapter mounted on a transducer (or to directly grip a portion of the transducer of corresponding design) and to snap into position by its terminal portions interlocking with recesses provided in corresponding external faces of the adapter. Preferably further means for firmly attaching the adapter to the attaching clip are provided at facing faces of the attaching clip and the adapter, such as a transverse ridge disposed on an external face of the adapter insertable into a facing transverse recess disposed in the attaching clip.
According to a preferred aspect of the invention the claws of the second prehensile organ are adapted to grip opposite sides of the locking clip in a way so as to hold it against the attaching clip and locking it in this position. Once snapped into position the locking element is not easily removed by hand from the attaching clip.
The locking element preferably comprises a front and back support areas, such as support faces, grids or similar, tilting in respect to each other, the back face facing the attaching clip whereas the front face faces the needle is preferably selectable to fit a particular type of transducer or needle insertion depth.
The needle assembly is mountable on the mounting assembly by attaching the journal clip to the locking element. Preferably the journal clip is mounted in a manner making it difficult or impossible to remove it from the locking element in a mounted position, for instance by snap tongues inserted into through openings in the locking element into which they lock and/or by snap tongues which can grip edges of the locking element.
It is preferred for the needle guide system of the invention to be easily detachable from a position mounted on a transducer only by damaging (breaking) a weak point, such as a fracture zone or line, of the mounting assembly. Particularly preferred is for such a weak point, kerf or facture zone to be comprised by the second prehensile means, in particular by one claw thereof.
It is preferred for the attaching clip to comprise breaking means for such destructive dismounting, the breaking means comprising a twisting element and a fracture zone or line. It is preferred for the fracture zone or line to be easily broken by displacement of sections adjacent to the zone or line in the direction of the transducer axis. Particularly preferred is the removal of a support for one or both second prehensile means providing for release of the locking element. By making the dismounting of the attaching clip conditional on its destruction the unsafe re-use of the needle assembly is prevented.
It is preferred for the revolver to comprise a multitude of needle receiving slots, for instance, three to six slots, each slot being dimensioned to receive a needle of different diameter. The revolver has about cylindrical shape with the slots disposed in its mantle in parallel with the cylinder axis and in an about equidistant manner along its circumference corresponding to an exactly equidistant manner in regard of the axes of their respective needles. Whereas the width of each slot corresponds closely to the diameter of the needle which it is intended to receive, its depth is slightly less than said diameter. Thereby the needle protrudes somewhat in a radial direction from the slot.
It is furthermore preferred for the revolver to comprise a multitude of locking elements. The locking elements, for instance, radially extending locking ribs, are arranged for locking the revolver in a position in which the a needle disposed in the slot of corresponding diameter is made abut a recess in a wall of the angular clip facing away from the transducer. Thereby the displacement of the needle is restricted to be strictly axial.
According to the present invention is also provided a disposable needle guide system comprising a needle guide assembly and a mounting assembly mountable on a transducer, the mounting assembly comprising an attaching clip mountable on a mounting portion of the transducer or on an adapter mountable on the transducer, and a locking clip mountable on the attaching clip so as to be releaseably held at its opposite ends by holding portions of the attaching clip, the release means including a kerf or other indication of fracture comprised by a support portion of the attaching clip supporting one of said holding portions and being easily breakable by hand. It is preferred for the release function to comprise a handle which can be turned to break the kerf or other indication of fracture and thereby irreversibly release the locking clip.
If not indicated otherwise, in this specification the orientation of the various elements of the needle guide system of the invention is in relation to the transducer. Ultrasound and other transducers are normally of a cylindrical, rectangular, parallelepipedeal or similar configuration for which a longitudinal axis can be defined. Directions perpendicular to that axis are termed xe2x80x9ctransversexe2x80x9d or xe2x80x9clateralxe2x80x9d. Faces facing the transducer are termed xe2x80x9cinteriorxe2x80x9d or xe2x80x9cinwardly facingxe2x80x9d or similar. Faces facing away from the transducer are termed xe2x80x9cexteriorxe2x80x9d or xe2x80x9coutwardly facingxe2x80x9d or similar.